Abalone: Shells prized for their iridescent (mother of pearl) linings. Abalones are found off the coasts of the USA and paua shells off New Zealand.
Agate (Chalcedony): Agates occur in nodular masses in rocks such as volcanic lavas. When split open, they reveal an amazing variety of colors and patterns and a distinctive banding that distinguishes agate from other kinds of chalcedony (the compact, micro-crystalline variety of quartz). The most famous area for agates is Idar-Oberstine in Germany, where agate has been collected since 1548. Most agate now comes from the deposits in Uruguay and Brazil. Moss agate occurs in India, China and the USA, where the most famous petrified wood is found in the Petrified Forest in Arizona. The usual colors and markings of agate made it very highly regarded by the ancients and revered throughout history. It was believed to make wearers “agreeable and persuasive and give them God’s favor.” The “eye” was believed to protect the wearer from the evil eye and was also seen as a cure for insomnia and could ensure good dreams.
Amber: Amber is not a stone but a fossilized tree sap or resin. It was one of the oldest substances used for personal adornment. Amber has been found in Stone Age excavations and has been recorded throughout history before, during, and since the ancient Greeks. It varies from transparent to semi-translucent and from yellow to dark brown in color. Occasionally, one can find “foreign” fragments or insects that were trapped in the amber, which usually increases its value. Amber is the lightest gem material and will float when dropped into a saturated salt solution.
Amethyst: Crystalline quartz in shades of purple, lilac, or mauve is called amethyst and was traditionally worn to guard against drunkenness and to instill a sober and serious mind. Some amethyst is heat treated to change the color to yellow, producing citrine. Crystals that are part citrine and part amethyst are called ametrine. It is found in alluvial deposits or in geodes. Some of the sites where it occurs are: Brazil, Canada, Sri Lanka, India, Uruguay, Madagascar, and the USA.
Aventurine: Aventurine, a ventura, "by chance" was discovered, by accident, in a Murano workshop during the seventeenth century. It is a manmade composition of glass. Tiny copper crystals are suspended in a glass base, then the raw aventurine is processed into canes, drawn out into flat sections like ribbons, then applied as decorations to the beads.
Azurite: Azurite is a copper ore that occurs in shades of green and blue, sometimes intermingled. Never clean Azurite or Malachite with any product containing ammonia. The ammonia will remove all of the polish of the stone.
Bloodstone: Also called heliotrope, the dark green Bloodstone is spotted with red because of the presence of iron oxides. India is the primary source, but it also occurs in Brazil, China, Australia and the USA. In the Middle Ages, bloodstone was attributed with special powers, as the spots were thought to be the blood of Jesus Christ.
Carnelian: Also called cornelian, this translucent reddish orange variety of chalcedony was thought to still the blood and calm the temper. Stones may be uniformly colored or banded. The best carnelian is from India, where it is placed in the sun to change brown tints to red.
Chrysoprase: Used by the Greeks and Romans, chrysoprase, a translucent apple green stone, is the most valued variety of chalcedony. Since 1965, the best material has come from Queensland (Australia). Other locales include: Brazil, California, the Urals (Russia) and Austria.
Citrine: Citrine is the yellow or golden yellow variety of quartz. Natural citrine is usually a pale yellow, but rare; most citrine in the market is heat-treated amethyst. The best material is found in Brazil, Spain, Madagascar, and the former USSR.
Coral: The skeletal remains of marine animals called coral polyps. Most corals—red, pink, white and blue varieties—are made up of calcium carbonate. Red coral is the most valuable and has been used in jewelry for thousands of years. Coral has been said to protect children, and parents may still give a gift of coral to their young children.
Dichroic: Refers to a gem or stone that appears to be two different colors or shades when viewed from different directions.
Fluorite: Formerly called fluorspar, it exists in a wide range of colors and frequently has more than one color in a single specimen, most often in shades of green to purple and yellow to golden brown. Though it also occurs in shades of pink and blue. A purple and yellow-banded variety called Blue John occurs in England. In the 18th century, fluorite was powdered in water to relieve the symptoms of kidney disease.
Garnet: Classed as a silicate, garnet is found throughout the world in rocks of many types. The reddest of all the garnet varieties is pyrope, derived from the Greek word that means “fire-like.” Garnet varies in shade from orange/red to a pinkish red to blackish red, deep crimson and violet red to green.
is considered a rare mineral, being found only in Gaspe’ Peninsula, Quebec,
Canada and an area north of Perth, Australia. Its light almost apple green
color is quite unique, though it may also contain portions of its brownish host
rock which give it a distinctive character. It is found as a secondary mineral
around nickel sulfide deposits.
Hematite: Hematite is an iron oxide, a metallic, opaque stone found in iron-mining areas. It usually occurs as an opaque material with a black metallic luster in igneous rocks around Lake Superior, Quebec, Brazil, Venezuela, and England. Powdered, it may be used as artist’s pigment or for polishing. In the past, it was worn as protection against bleeding.
Howlite: Howlite is a soft, light mineral with a chalky white color, commonly with black or brown veins. It is very porous and may often be dyed. It has been found in large quantities in the USA (California).
Inclusions: Markings or foreign bodies found within a stone.
Iolite: Violet-blue iolite has been called water sapphire because of its similarity to blue sapphire when cut. Iolite is found in alluvial deposits as small, transparent, waterworn pebbles in Sri Lanka, Myanmar, Madagascar and India.
Iridescence: Reflection of light off internal features in a stone, giving rise to a rainbowlike play of colors.
Jasper: Jasper is a massive, fine-grained, opaque variety of chalcedony, believed to protect against sight defects and drought. It occurs in shades of brown, grayish blue, red, yellow, and green. Usually it is marked with an almost blotchlike or veinlike pattern. Jasper was believed in ancient cultures to bring rain and to protect its wearer from the bites of poisonous creatures.
Labradorite: Labradorite is a form of feldspar. It may be orange, yellow, colorless, or red but shows a play of color. It occurs in metamorphic and igneous rocks in Labrador (Canada), Finland, Norway, and the former USSR.
Lapis Lazuli: Lapis lazuli is a blue rock made up of several different materials, including lazurite, sodalite, hauyne, calcite, and pyrite. The composition and color of lapis varies, but it is the intense dark blue, with minor patches of white calcite and brassy yellow pyrite, that is considered to be the best quality. The best quality lapis is from Afghanistan. It has long been worn in the belief that it will protect the wearer from evil.
Lampwork: Is hot glasswork that began as far back as 1400 BCE in Egypt and possibly before that. The word “lamp” came from the oil lamps that were once used before today’s modern torch. Glass is melted in a torch flame and wound onto a mandrel (a thin steel rod), then beads are put into a kiln to slowly anneal and cool to prevent breaks and cracks.
Lepidolite: This stone, also called "Lavenderine," is a byproduct of the mining of lithium. The stones' pink to violet/gray coloration is said to have a calming effect and relax the nerves. It is usually found in granite and is mined at Minas Gerais (Brazil), California, Connecticut, New Mexico and South Dakota (USA), Madagascar, Zimbabwe, the USSR, Australia, Sweden and Japan.
Malachite: Malachite is a copper ore that comes in a brilliant Kelly green, marked with bands or concentric striping in contrasting shades of the same basic green. In ancient times it was thought to ease the teething pain of children and women in labor. It was also believed capable of protecting from the evil eye and bringing good luck.
Marcasite: Marcasite is a tiny, glittering stone with a brassy-colored luster. It is a relative of hematite.
Matrix: The rock in which a gem is found. Also known as host or parent rock.
Moonstone: Moonstone is the opalescent variety of feldspar, with a blue or white sheen, rather like the shine of the moon. The best material is from Myanmar and Sri Lanka. Moon worshippers through the ages have used it in their jewelry. It is believed to arouse one’s tender passion and to give lovers the ability to foretell their future. To get this information, however, legend has it that the stone must be placed in the mouth while the moon is full.
Nephrite (Jade): Recognized since 1863, as a separate type of jade, Nephrite is found in aggregates of fibrous crystals. Colors vary from a dark green to a cream color.
Onyx, Sard and Sardonyx (Chalcedony): Onyx, sard, and sardonyx are all varieties of the microcrystalline quartz, chalcedony. Onyx is similar to agate but has straight rather than curved bands. These may be brown and white or black and white. The “black onyx” that is commonly used in jewelry isn’t onyx at all, and isn’t naturally black. It is chalcedony dyed black. It is always dyed and may be banded or solid black. Sard is a brownish red variety and Sardonyx is a blend of sard and onyx and has the straight white bands of onyx and the brownish red of sard. It is found worldwide and is formed by the deposition of silica in gas cavities in lavas, which results in the distinctive bands. Onyx seals were very popular with the Romans.
Pearl: Pearls are formed in shellfish—especially oysters and mussels—as a natural defense against an irritant. An irritant is introduced to initiate the formation of a cultured pearl. Natural pearls have been harvested from the Persian Gulf, the Gulf of Manaar (Indian Ocean), and the Red Sea for thousands of years. The coasts of Polynesia and Australia produce mainly cultured pearls. Both freshwater and saltwater pearls are cultivated in Japan and China. Freshwater pearls occur in the rivers of Scotland, Ireland, France, Austria, Germany, and the USA (Mississippi).
Peridot: Peridot has an olive or bottle green color due to the presence of iron, and a distinctive oily or greasy luster. The Crusaders brought peridot to Europe in the Middle Ages from St. John’s Island (Egypt) in the Red Sea, where it had been mined for over 3,500 years. Sources of peridot include Egypt, China, Myanmar, Brazil, Norway, the USA, Australia, and South Africa. Small pebbles of peridot found in parts of Arizona and New Mexico are known locally as Job’s tears.
Rhodonite: Rhodonite has a distinct pink or rose red color, often containing black veins. The name comes from rhodos, the Greek for “rose.”
Rose Quartz: Pink or peach-colored quartz is called rose quartz. Its color is thought to be due to the presence of small amounts of titanium. The best material is found in Madagascar. It is also found in Brazil, the USA, the former USSR, Scotland, and Spain.
Serpentine: The name serpentine refers to a group of predominantly green minerals that occur in masses of tiny intergrown crystals. It is often used as a jade substitute. The two main types used in jewelry are bowenite (also called “new jade” which is a translucent green or blue-green) and the rarer williamsite (translucent, oily green, veined or spotted with inclusions). Amulets of serpentine were worn for protection from serpent bites, stings of poisonous reptiles and poison in general.
Smoky Quartz: Brown quartz includes quartz of a light brown or dark brown color, grayish brown “smoky” quartz and the black variety called morion. Brown or smoky quartz from the Cairngorm Mountains of Scotland is called cairngorm. It has been found in Brazil, Madagascar, the Swiss Alps, the USA (Colorado), Australia and Spain.
Sodalite: Sodalite, whose name reflects its sodium content, is found in all shades of blue. It may contain white streaks of the mineral calcite. The most important commercial site for sodalite is Bancroft in Ontario, Canada. It was discovered during a royal visit by Princess Margaret of England. For this reason, sodalite from Bancroft is sometimes called Princess Blue.
Sunstone: A beautiful, shimmering red to orange variety of feldspar has been mined in Oregon.
Tiger’s Eye: More commonly known as chatoyant quartz, “Tiger’s-eye” is black, with iron oxide staining that gives yellow and golden brown stripes. It is commonly found in Australia and the USA. Increased iron oxide staining also produces a reddish/brown color.
Topaz: Topaz occurs in a range of colors from deep golden yellow, to pink, blue, green and colorless. It occurs in igneous rocks and volcanic lavas. The name “topaz” is thought to be derived from the Sanskrit word tapas, meaning fire.
Turquoise: One of the first gemstones to be mined, turquoise is composed of hydrated copper and aluminum phosphate. Its name originated in medieval Europe, where traders from Turkey introduced the blue-green gemstones as an exotic luxury. Turquoise tends to form in arid, mountainous regions, such as those found in Persia, Central Asia, and the American Southwest. The relative value of a particular stone is based on its density, color, matrix, and rarity. It can vary in color from shades of greens to the highly prized robin’s egg blue. Turquoise has long been thought to be sacred and as having mystical and medicinal powers.
Watermelon Tourmaline: Tourmaline crystals with a pink center and a green rim, or vice versa, are called watermelon tourmaline, because their coloring is similar to the pink flesh and green rind of a watermelon. It is found in South Africa, Brazil, East Africa, and in many other localities. Parti- and multicolored tourmaline is carved or cut and polished to show off the different colors to best effect.
Hall, Cally. Gemstones. 2nd American Edition, Dorling Kindersley, Inc., New York, 2002.
Lowry, Joe Dan and Lowry, Joe P. Turquoise Unearthed, An Illustrated Guide. Rio Nuevo Publishers, Tucson, Arizona, 2002.
Pellant, Chris with Phillips, Roger. Rocks, Minerals & Fossils of the World. Little Brown and Company, Boston, 1990.
Whitlock, Herbert P. The Story of Gems. Dover Publications, Inc., Mineola, New York, 1997.
Coles, Janet and Budwig, Robert. Beads: An Exploration of Bead Traditions Around the World. Simon and Schuster, New York, 1997.
Dubin, Lois Sherr. The History of Beads, Concise Edition. (From 30,000 B.C. to the Present). Harry N. Abrams, Inc., New York, 1995.
Francis, Jr., Peter. Beads of the World. 2nd Edition, Schiffer Publishing Ltd., Atglen, Pennsylvania, 1999.